CBQE-2186: add json rq output to reporting tool

Change-Id: Iefc5f3f36b71cd964b44759d578f279048d77341
Reviewed-on: http://review.couchbase.org/35369
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>